Financial documents evidencing transactions involving banking institutions typically are subjected to two complementary processes. The first involves the capturing of data from the document, and imprinting thereon encoded data in a Magnetic Ink Character Recognition (MICR) format, for example, E13B or 1403 fonts in human readable form.
A further simplification allowing higher speed processing of financial documents is the addition of magnetic ink bar-codes in machine readable form as disclosed in U.S. Pat. No. 3,703,628 and copending application Ser. No. 448,458, filed Mar. 6, 1974, now abandoned.
After the data has been captured, encoded, and reprinted upon the face or back of a document with magnetic ink, subsequent transactions may require repeated sorting and classification of large quantities of the encoded documents. High speed sorting processes in the prior art include the reading of encoded data by a MICR reader, an Optical Character Recognition reader (OCR), or a redundant reading system which merges the recognition signals of MICR and OCR readers.
U.S. Pat. No. 3,764,978 discloses a system for character recognition in which a plurality of MICR characters are recognized both magnetically and optically. When the magnetic reader fails to recognize a character and the optical reader is successful in recognizing it, the optical character signal is generated for further processing. If the optical reader fails to recognize a character and the magnetic reader is successful, then the identification signal generated corresponds to the character recognized by the magnetic reader. However, when the magnetic and optical readers generate different character recognition signals for the same character image, an ambiguity results which is either resolved by generating a reject signal, or a choice is made between the optical and magnetic recognition signals based upon criteria dictated by the particular application and print font used.
A merged MICR/OCR system significantly decreases the number of rejects occurring during the sorting of a high velocity train of documents. However, the remaining number of rejects generated from valid data fields, and the ambiguous results caused by conflicting recognition signals are still prohibitive to those banking institutions handling large volume transactions daily. Although criteria characterizing a particular application may be formulated, the multifarious aspects of the daily financial transactions make the choice between conflicting magnetic and optical recognition signals too complex to be treated generally. Further, damage to a MICR data field occurring between a data capture operation and subsequent reprocessing may cause a document to be rejected.